Hi @hauserjoci,
I had the same situation, except my Octavia was not an RS, it is "only" Elegance, but the headunit situation was the same. The MIB1 Columbus display is perfect for you, it can stay the original if you want, I use the original MIB1 display with a MIB2.5 Amundsen unit and works well. You need to change the headunit in the glovebox and if the canton amplifier (under the drivers seat) is a specific type, you need to change to a MIB2 amp. I needed to change the BCM also, because my old one was not compatible with the facelift headunit and I had internal light issues. I found a nice guy in Hungary, who had made all the things in my car and now it is fully working.
If I'm correct, all unit is Canton compatible, the difference is only a dataset on the unit but I'm not 100% sure with this info, I'm not a professional.
There is one more (cheaper) option to have Android auto in your car, but it is not a Skoda solution (it's third party), so I don't want to post it here, write a pm and I can explain it for you.
Andras